Detailed structural investigations are being carried out on several glycoproteins with the aim of characterizing the nature of the carbohydrate units and of the glycopeptide bands present in the molecules. Both soluble and insoluble carbohydrate-containing proteins are under study. These include plasma proteins, thyroglobulin, collagens and the glycoprotein components of various basement membranes and plasma membranes. An attempt will be made to correlate structure and function of the cell surface glycoproteins under study.